Magnesium extraction



Patented June 2, 1925.

UNITED STATES PATENT OFFl-QE.

' BRODDE n r. nnonm, or cunwnLL, NEW JERSEY.

MAGNESIUM EXTRACT1011.

No Drawing.

is a specification.

This invention relates particularly to the extraction of magnesium from magnesium alloys.

Under certain circumstances, for instance in the case of an over-supply of magnesium alloys, it may be that the magnesium content of the alloy may be of more value or more in demand than the alloy itself. The purpose of the invention therefore is toprovide an inexpensive and practical method for effecting the separation of the magnesium from other elements with which it has been combined. v

The process has been found particularly practicable with the zinc, magnesium alloys and will therefore be described as applied to such alloys. i

Magnesium is one of the few metals that completely resists or is unaffected by the alkalis; metals as zinc, on the other hand, readily reactwith an alkali.

Briefly stated, the invention involves the subjection of. the alloy to treatment in a molten alkali which causes the zinc orother metal in the treated alloy to react with the alkali and in the course of the same reaction the magnesium to separate'itself from the other metal or metals and remain dis-- associated from'the' alkali. I

Considering apractical illustration: A bath of molten alkali, whichmay be either sodium hydroxide or potassium hydroxide is prepared in a kettle of cast iron or other suitable material and brought to.

a heat which need be only sufficient to initiate the reactions since the process becomes exothermic and sufiicient heat to com lete the operations is the reactions proc sgpplied automatica y as The'alloy may be' supplied to the molten alkali either in the solid or in the molten Application filed ma 13,

metal.

1924. Serial li'o. 712,980.

alkali, reacts immediately with the alkali into zincate and hydrogen and the neu. trality of the magnesium for the alkali results in the magnesium, in the presence ofi nascent hydrogen, separating in a practically' pure state and floating to the top, where it can be readily removed.

As all magnesium produced by electrolytic decomposition has to undergo purificaf tion before being sold as a-com-mercial proclnot or before being used for alloying purposes, it may prove advantageous to add a small percentage of zinc tosuch crude magnesium and then proceed with the alkali purification process as above disclosed.

Magnesium in an extremely pure state-can be produced by this process with very simple equipment.

What is claimed is:

1. The process of extracting magnesium from magnesium alloys which comprises treating such alloys ina bath of molten alkali having chemical aflinity for the metal or metals with which the magnesium' is alloyed and for which the magnesium has a natural chemical neutrality, V

2. The process of extracting magnesium from magnesium containing allo s which ten alkaliand the introduction into such comprisesthe preparation of a bat of mol-f bath of the magnesium containing alloy in condition and quantity to; control the exothermic action resulting from such combination.

3. The process of extracting magnesium from magnesium-zinc alloys which comprises introducing such-alloys at' a regulated rate into a molten alkali bathoof sodium or potassium hyd ro'xide and mechanically removing the metallic magnesium released In the ensuing reaction.

4. The process of from magnesium containing alloys which comprises treating such alloys exothermical- 1y with a molten alkali having a chemical aflinity for the metal or metals other than the magnesium in the alloy and a natural chemical neutrality for the "magnesium, thereby efi'ecting complete separation of the magnesium and floatation of the same and thereafter removing said separated floated 5. In the prepara ion of magnesium, the

extracting magnesium processwhich inclu les allo 'ng with magnesium a metal lving ,c emical aflinity form alkali which has a natural chemical,

' neutrality for magnesium and then treat-- from magnesium alloys which comprises treating such alloys in a bath of molten alkali having chemical aflinity for the metal or metals with which the magnesium is alloyed and for which the ma'gn'esium has a natural chemical neutrality and producing a combination of the alloying metal or metals with the'alkali and a separation of to ma process which includes the addition of zinc esium and the treatment in a bath of mo ten alkali to produce a combination of the zinc with the alkali and the separa-' BRODDE E. F. RHODIN. 

